1. Field of the Invention
The present invention relates generally to shaft couplings and, more particularly, to shaft couplings with adjustment means perpendicular to the shaft.
2. Description of the Related Art
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Shafts are used in many different mechanical devices and may be used for different purposes. For example, a drive shaft may be used to transfer torque from a combustion engine to wheels of a vehicle to move the vehicle. Alternatively, a shaft may be used as a support member to hold other members or devices in a particular position and/or, in some instances, may be used as an axis for rotation. In yet other applications, a bearing housing may be attached to the shaft to reduce the amount of friction caused by rotation of a shaft.
Additionally, although shafts may take on several different shapes, one common shape is a cylinder. Many applications that use cylindrical shafts require a component or member to be coupled to the shaft so that it may move in conjunction with the shaft (or vice-versa) and/or so that it does not move longitudinally along the shaft, among other reasons. Several different techniques have been developed to rigidly couple components or members to cylindrical shafts. For example, keys, spines, and flats are common shaft configurations that allow for a rigid coupling with a cylindrical shaft. Generally, keys, spines and flats are non-circular portions of a shaft that corresponds with non-circular portions in a bore of the member that is to be coupled with the shaft. The non-circular portions of the shaft and the member coupled to shaft allow for the member to move in conjunction with the shaft. The resultant fit between the shaft and the bore produces large radial forces applied by the bore of the coupling member normal to the shaft diameter, which locks the coupled member to the shaft.
An alternative technique is an interference fit, wherein the shaft and the bore of the member coupled to the shaft are manufactured to have a very tight tolerance. Stated differently, the bore does not provide much clearance for the shaft. Because of the tight tolerance, the coupling of the member and the shaft requires the application of a high amount of pressure, the temporary expanding of the bore through heating, or a combination of pressure and heat to allow the shaft to fit into the bore.
Another alternative technique for coupling members to a cylindrical shaft is using a split ring and bolt or screw. The split ring fits around the shaft and is clamped down on the shaft by tightening the bolt or screw. Producing a frictional coupling. An alternative technique involves using one or more set screws, or similar threaded devices, within the coupled member which, when tightened, bear directly on the shaft, and produce a frictional or mechanical coupling.
The use of keys, spines, flats, interference fits, and/or split ring couplers have disadvantages, however. First, the use of keys, spines or flats includes modifications to the shaft that may weaken the shaft. Similarly, because the split rings are not unitary members, they may lack structural integrity. Set screws, which bear directly on the shaft, often cause damage to the shaft. It may also be difficult to configure sufficient quantity and screw size to intersect the shaft and generate the desired frictional force. Alternatively, the use of an interference fit may increase the difficulty associated with assembling the shaft and member, as well as complicating the replacement of the member or the shaft.
Embodiments of the present invention may address one or more of the issues mentioned above.